Stephen Arnold Douglas (April 23, 1813 – June 3, 1861) was an American politician from Illinois. He was a U.S. Representative, a U.S. Senator, and the Democratic Party nominee for President in the 1860 election, losing to Republican Abraham Lincoln.

Douglas had previously defeated Lincoln in a Senate contest, noted for the famous Lincoln-Douglas debates of 1858. He was nicknamed the "Little Giant" because though short in physical stature, he was a forceful and even dominant figure in politics.